Comparative study of DAM and ELM to one-storey eccentrically braced frames subjected to seismic load in Indonesia

Abstract

Indonesia is late in updating its structural steel building design code to AISC 360-10. Revision was done in 2015 replacing the 2002 code. The new version changes the method of steel stability analysis from effective length method (ELM) to direct analysis method (DAM). The 2015 code implements DAM, which is based on second-order elastic analysis which directly calculates P-delta effect in analysis. DAM takes into account geometric imperfection and strength reduction. Notional load as 0.002 of gravity load should be applied horizontally to represent geometric imperfection. It is allowed to adjust the notional load coefficient. Numerical study has been conducted to compare the use of DAM and ELM on eccentricallybraced frame subjected to Indonesian seismic load. Different values of notional load coefficient are considered. Experimental results conducted by other researchers were used as reference. The frames were reanalysed using four different stability methods: ELM first-order analysis, ELM second-order analysis and DAM with different notional load coefficients: 0.002 and 0.003.